The two incumbents were forced into the same district when Louisiana lost a congressional seat because of anemic population growth in the latest federal census. The state will have six U.S. House seats in the new term that begins in January.

A four-term congressman who had gone into Saturday's balloting favored by the new district design, Boustany will represent the 3rd District covering southwest Louisana and nearby Acadiana.

With nearly all precincts reporting, Boustany led Landry by about a 3-2 margin. About one-fifth of district voters cast ballots on Saturday.

"This looks like a very solid victory. We had a very strong ground game, which was a key element in the runoff. We reached out to a lot of voters with a solid message backed by the results I've gotten in Congress," said Boustany, a retired doctor.

Landry, the tea party favorite, was unable to build enough grassroots support in his bid to oust Boustany. The race had been marked by sharp attacks since both men ran as conservative Republicans opposed to the policies of President Barack Obama and had little philosophical ground in which to distinguish themselves.

Pearson Cross, chairman of the political science department at the University of Louisiana-Lafayette, said Boustany was the "de-facto incumbent" throughout the race.

"Most voters in the district have voted for Charles Boustany, think he's done a good job, are comfortable with him," Cross said.

Landry said it was difficult to overcome Boustany's advantage in the district design. Boustany had represented more than two-thirds of the parishes in the configuration of the new 3rd District.

Though they had three other challengers in the November election, the two congressmen had campaigned as though it were a two-man race for months.

Boustany cast his GOP opponent as a good ol' boy politician who would say anything to get elected, habitually skipped votes in Congress and spread distortions about Boustany's record to distract voters from his own lack of accomplishments.

Landry criticized Boustany as lacking the courage to make tough votes for his district and instead following in lockstep with Republican leaders even if south Louisiana voters didn't support the policy.

The race was one of Louisiana's most expensive congressional contests, with nearly $6 million spent between the two and even more from outside groups. Boustany had a significant edge in fundraising, raising nearly $2 million more than Landry, according to campaign finance reports filed with the Federal Election Commission.

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